Delaware Lawn Mowing Service

Fertilizer: Understanding Labels

Federal and state laws require that all fertilizer labels supply the same information. Once you know the code, reading a label is easy.

Analysis: All fertilizer packages display three numbers, the fertilizer’s analysis. The analysis refers to three essential nutrients: nitrogen, phosphorus, and potassium. Each number stands for the percent of the package made up of the available form of each nutrient by weight. The analysis shows the nutrients as a ration to one another. For example, a 29-3-4 fertilizer has approximately a 10-1-1 ratio. How do you compare two fertilizers with the same analysis ratio? Look at the pounds of nitrogen delivered per thousand square feet and the source of the nitrogen.

To convert the analysis to pounds of nitrogen, multiply the package weight by the percentage of nitrogen. For example, a typical 15.5 pound bag of 29-3-4 holds 4.5 pounds of nitrogen (15 1/2 * 29%). Divide that number by the number of 1,000 square foot units the bag covers – 5 for the 5,000 square foot coverage of a 15.5 pound bag – and you see that 29-3-4 fertilizer supplies 9/10 pound of nitrogen per 1,000 square feet (4.5 pounds / 5).

The available forms of phosphorus and potassium are P2O5 and K20. Determining their actual amounts in a fertilizer is less straightforward and rarely necessary.

Surge vs. Steady Growth:

Surge Growth: Fast-release fertilizers dissolve and move quickly. Grass grows rapidly, then slows.

Steady Growth: Slow-release fertilizers dissolve slowly. They spoon-feed nutrients, so the grass has steady, controlled growth.

  • Inorganic fast-release sources are salts that pull water from the air; they provide quick growth.
  • Liquid fertilizers contain fast-release nitrogen, which must be reapplied often.
  • Slow-release sources are safer to plants. Uniformly sized particles are easy to spread.

Liquid Or Dry?

Fertilizer can be applied to a lawn in liquid or dry form. People often ask which is best. The truth is, lawns down’t care, both contain the same materials and both provide satisfactory results, although liquids are quick release fertilizers and must be applied more frequently.

The question is more a matter of convenience and skill. It takes more skill to uniformly apply liquid fertilizer at the right rate. Most homeowners generally find dry materials easier to handle, especially if they have a good spreader that accurately and uniformly distributes the fertilizer.

Of course if you need grass cutting, we can help.

Stewart Bros. Turf, LLC
Servicing Wimington, Brandywine, Pike Creek, Newark, Hockessin, Delaware